High-precision, low-power temperature coefficient calibration device and battery management chip

Abstract

The present disclosure provides a high-precision, low-power temperature coefficient calibration device, which obtains the temperature coefficient change of the discharge calibration MOS transistor based on the voltage between the source and the drain of the discharge calibration MOS transistor and obtains the temperature coefficient change of the discharge MOS transistor according to the relationship between the discharge calibration MOS transistor and the discharge MOS transistor, and / or obtains the temperature coefficient change of the charge calibration MOS transistor based on the voltage between the source and the drain of the charge calibration MOS transistor and obtains the temperature coefficient change of the charge MOS transistor according to the relationship between the charge calibration MOS transistor and the charge MOS transistor. The present disclosure also provides a battery management chip.

Description

Technical Field

[0001] The present disclosure provides a high-precision, low-power consumption temperature coefficient calibration device and a battery management chip. Background Art

[0002] When using a battery pack such as a lithium battery, it is necessary to detect the charging current and the discharging current in order to prevent overcharging or overdischarging. Overcharging may cause an explosion, and overdischarging may shorten the battery life.

[0003] The detection method currently used is mostly to connect a detection resistor in series, but the detection resistor consumes a lot of energy and also increases the cost, and the detection accuracy is not high, at least because the resistance of the detection resistor changes with the temperature.

[0004] In addition, in the prior art, there is also a method of using the on-resistance of the charging transistor and the discharging transistor to perform current detection, but this method is also affected by temperature, that is, the on-resistance will change with the change of temperature.

[0005] Therefore, how to design a simple and effective charging and discharging current detection method and eliminate the influence of temperature coefficient is a technical problem that needs to be solved, so as to achieve high-precision current sampling. Summary of the invention

[0006] In order to solve one of the above technical problems, the present disclosure provides a high-precision, low-power consumption temperature coefficient calibration device and a battery management chip.

[0007] According to one aspect of the present disclosure, a temperature coefficient calibration device is provided for calibrating the temperature coefficient of a MOS transistor, wherein the MOS transistor is a charging MOS transistor and a discharging MOS transistor for controlling the charging and discharging of a battery / battery pack, wherein the drain of the charging MOS transistor and the drain of the discharging MOS transistor are connected to form a series circuit, comprising:

[0008] a discharge calibration MOS transistor and / or a charge calibration MOS transistor, wherein the drain of the discharge calibration MOS transistor is connected to the drain of the discharge MOS transistor, and / or the drain of the charge calibration MOS transistor is connected to the drain of the charge MOS transistor;

[0009] a first current source connected to a source of the discharge calibration MOS transistor and / or connected to a source of the charge calibration MOS transistor; and

[0010] A calibration unit, wherein the calibration unit obtains a temperature coefficient change of the discharge calibration MOS transistor based on a voltage between a source and a drain of the discharge calibration MOS transistor and obtains the temperature coefficient change of the discharge MOS transistor according to a relationship between the discharge calibration MOS transistor and the discharge MOS transistor, and / or obtains a temperature coefficient change of the charge calibration MOS transistor based on a voltage between a source and a drain of the charge calibration MOS transistor and obtains the temperature coefficient change of the charge MOS transistor according to a relationship between the charge calibration MOS transistor and the charge MOS transistor.

[0011] According to at least one embodiment of the present disclosure, the charging MOS transistor, the discharging MOS transistor, the discharging calibration MOS transistor and the charging calibration MOS transistor are MOS transistors of the same type, and the channel aspect ratio and / or the number of cells of the discharging MOS transistor are proportional to the channel aspect ratio and / or the number of cells of the discharging calibration MOS transistor, and the channel aspect ratio and / or the number of cells of the charging MOS transistor are proportional to the channel aspect ratio and / or the number of cells of the charging calibration MOS transistor.

[0012] According to at least one embodiment of the present disclosure, a first resistor is further included, wherein the first resistor is a zero temperature coefficient resistor or a low temperature coefficient resistor, one end of the first resistor is connected to the second current source, and the other end is connected to the negative terminal of the battery pack.

[0013] According to at least one embodiment of the present disclosure, the first current source and the second current source are the same current source or different current sources. In the case of different current sources, the current value of the first calibration current provided by the first current source and the current value of the second calibration current provided by the second current source are equal or unequal.

[0014] According to at least one embodiment of the present disclosure, the method further includes:

[0015] a first analog-to-digital converter, which obtains a voltage across the first resistor, and a voltage between a source of the discharge calibration MOS transistor and / or a source of the charge calibration MOS transistor and a negative terminal of a battery / battery pack or a negative terminal of a load / charging terminal; and

[0016] a second analog-to-digital converter, the second analog-to-digital converter directly or indirectly acquiring a voltage between a source and a drain of a charge calibration MOS transistor and / or a voltage between a source and a drain of a discharge calibration MOS transistor,

[0017] The first analog-to-digital converter and the second analog-to-digital converter are different analog-to-digital converters or the same analog-to-digital converters.

[0018] According to at least one embodiment of the present disclosure, the number of the discharge calibration MOS transistor is one.

[0019] According to at least one embodiment of the present disclosure, when the temperature coefficient of the discharge MOS transistor is calibrated, the discharge calibration MOS transistor and the discharge MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source of the discharge MOS transistor and the source of the charging MOS transistor, and obtains the temperature coefficient change of the discharge calibration MOS transistor based on the voltage between the source and the drain of the discharge calibration MOS transistor, the voltage between the source and the drain of the discharge MOS transistor, and the voltage across the first resistor.

[0020] According to at least one embodiment of the present disclosure, in the case of including a discharge calibration MOS transistor and a charge calibration MOS transistor, the drains of the discharge calibration MOS transistor and the charge calibration MOS transistor are both connected to the drain of the discharge MOS transistor, and in the case of calibrating the temperature coefficient of the discharge MOS transistor, the discharge calibration MOS transistor, the discharge MOS transistor and the charge calibration MOS transistor are turned on, and the second analog-to-digital converter measures a first voltage between the source of the discharge MOS transistor and the source of the charge calibration MOS transistor, and obtains a change in the temperature coefficient of the discharge calibration MOS transistor based on the first voltage and the voltage across the first resistor.

[0021] According to at least one embodiment of the present disclosure, when the temperature coefficient of the discharge MOS transistor is calibrated, the discharge calibration MOS transistor and the discharge MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the discharge MOS transistor or measures the voltage between the source and the drain of the discharge calibration MOS transistor, and combines the voltage between the source and the drain of the discharge MOS transistor and the voltage across the first resistor to obtain the change in the temperature coefficient of the discharge calibration MOS transistor.

[0022] According to at least one embodiment of the present disclosure, the number of the charging calibration MOS transistor is one.

[0023] According to at least one embodiment of the present disclosure, when the temperature coefficient of the charging MOS transistor is calibrated, the charging calibration MOS transistor and the charging MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source of the discharge MOS transistor and the source of the charging MOS transistor, and obtains the temperature coefficient change of the charging calibration MOS transistor based on the voltage between the source and the drain of the charging calibration MOS transistor, the voltage between the source and the drain of the charging MOS transistor, and the voltage across the first resistor.

[0024] According to at least one embodiment of the present disclosure, in the case of including a discharge calibration MOS transistor and a charge calibration MOS transistor, the drains of the charge calibration MOS transistor and the discharge calibration MOS transistor are both connected to the drain of the charge MOS transistor, and in the case of calibrating the temperature coefficient of the charge MOS transistor, the charge calibration MOS transistor, the charge MOS transistor and the discharge calibration MOS transistor are turned on, and the second analog-to-digital converter measures a second voltage between the source of the charge MOS transistor and the source of the discharge calibration MOS transistor, and obtains the temperature coefficient change of the charge calibration MOS transistor based on the second voltage and the voltage across the first resistor.

[0025] According to at least one embodiment of the present disclosure, when the temperature coefficient of the charging MOS transistor is calibrated, the charging calibration MOS transistor and the charging MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the discharging MOS transistor or the voltage between the source and the drain of the charging calibration MOS transistor, and combines the voltage between the source and the drain of the charging MOS transistor and the voltage across the first resistor to obtain the temperature coefficient change of the charging calibration MOS transistor.

[0026] According to at least one embodiment of the present disclosure, the number of the discharge calibration MOS transistors is two, and a first discharge calibration MOS transistor and a second discharge calibration MOS transistor of the two discharge calibration MOS transistors are both connected to the drain of the discharge MOS transistor, and the source of the first discharge calibration MOS transistor is connected to the first current source, and the source of the second discharge calibration MOS transistor is connected to the negative terminal of the battery / battery pack.

[0027] According to at least one embodiment of the present disclosure, when the temperature coefficient of the discharge MOS transistor is calibrated, the discharge MOS transistor, the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are all turned on, the second analog-to-digital converter measures a third voltage between the source and the drain of the second discharge calibration MOS transistor, and the first analog-to-digital converter measures a fourth voltage between the source of the first discharge calibration MOS transistor and the source of the second discharge calibration MOS transistor, and the change in the temperature coefficient of the discharge calibration MOS transistor is obtained based on the third voltage, the fourth voltage, and the voltage across the first resistor.

[0028] According to at least one embodiment of the present disclosure, when the temperature coefficient of the discharge MOS transistor is calibrated, the discharge MOS transistor, the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are all turned on, the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are the same MOS transistor, and a fourth voltage between the source of the first discharge calibration MOS transistor and the source of the second discharge calibration MOS transistor is measured by the first analog-to-digital converter, and the change in the temperature coefficient of the discharge calibration MOS transistor is obtained according to the fourth voltage and the voltage across the first resistor.

[0029] According to at least one embodiment of the present disclosure, when the temperature coefficient of the discharge MOS transistor is calibrated, the discharge MOS transistor, the first discharge calibration MOS transistor, and the second discharge calibration MOS transistor are all turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the first discharge calibration MOS transistor, the voltage between the source of the first discharge calibration MOS transistor and the source of the second discharge calibration MOS transistor, the voltage between the source and the drain of the discharge MOS transistor, or the voltage between the source of the discharge MOS transistor and the source of the charge MOS transistor;

[0030] The first analog-to-digital converter measures a fourth voltage between a source of the first discharge calibration MOS transistor and a source of the second discharge calibration MOS transistor,

[0031] The temperature coefficient change of the discharge calibration MOS transistor is obtained according to the voltage measured by the second analog-to-digital converter, the fourth voltage, and the voltage across the first resistor.

[0032] According to at least one embodiment of the present disclosure, when a charging calibration MOS transistor is included, the charging calibration MOS transistor is turned on, and the second analog-to-digital converter measures the voltage between the source of the second discharge calibration MOS transistor and the source of the charging calibration MOS transistor to obtain the third voltage.

[0033] According to at least one embodiment of the present disclosure, the number of the charging calibration MOS transistors is two, and a first charging calibration MOS transistor and a second charging calibration MOS transistor of the two charging calibration MOS transistors are both connected to the drain of the charging MOS transistor, and the source of the first charging calibration MOS transistor is connected to the first current source, and the source of the second charging calibration MOS transistor is connected to the negative terminal of the battery / battery pack or the negative terminal of the load / charger.

[0034] According to at least one embodiment of the present disclosure, when the temperature coefficient of the charging MOS transistor is calibrated, the charging MOS transistor, the first charging calibration MOS transistor and the second charging calibration MOS transistor are all turned on, the second analog-to-digital converter measures a fifth voltage between the source and the drain of the second charging calibration MOS transistor, and the first analog-to-digital converter measures a sixth voltage between the source of the first charging calibration MOS transistor and the source of the second charging calibration MOS transistor, and the temperature coefficient change of the charging calibration MOS transistor is obtained according to the fifth voltage, the sixth voltage, and the voltage across the first resistor.

[0035] According to at least one embodiment of the present disclosure, when the temperature coefficient of the charging MOS transistor is calibrated, the charging MOS transistor, the first charging calibration MOS transistor and the second charging calibration MOS transistor are all turned on, the first charging calibration MOS transistor and the second charging calibration MOS transistor are the same MOS transistor, and a sixth voltage between the source of the first charging calibration MOS transistor and the source of the second charging calibration MOS transistor is measured by the first analog-to-digital converter, and the change in the temperature coefficient of the charging calibration MOS transistor is obtained based on the sixth voltage and the voltage across the first resistor.

[0036] According to at least one embodiment of the present disclosure, when the temperature coefficient of the charging MOS transistor is calibrated, the charging MOS transistor, the first charging calibration MOS transistor, and the second charging calibration MOS transistor are all turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the first charging calibration MOS transistor, the voltage between the source of the first charging calibration MOS transistor and the source of the second charging calibration MOS transistor, the voltage between the source and the drain of the charging MOS transistor, or the voltage between the source of the charging MOS transistor and the source of the discharging MOS transistor;

[0037] The first analog-to-digital converter measures a sixth voltage between a source of the first charging calibration MOS transistor and a source of a second charging calibration MOS transistor,

[0038] The temperature coefficient change of the charge calibration MOS transistor is obtained according to the voltage measured by the second analog-to-digital converter, the sixth voltage, and the voltage across the first resistor.

[0039] According to at least one embodiment of the present disclosure, when a discharge calibration MOS transistor is included, the discharge calibration MOS transistor is turned on, and the second analog-to-digital converter measures a voltage between a source of the second charge calibration MOS transistor and a source of the discharge calibration MOS transistor to obtain the fifth voltage.

[0040] According to at least one embodiment of the present disclosure, the channel length-to-width ratio and / or the number of cells of the discharge calibration MOS transistor is 1:M with the channel length-to-width ratio and / or the number of cells of the discharge MOS transistor, and / or the channel length-to-width ratio and / or the number of cells of the charge calibration MOS transistor is 1:M with the channel length-to-width ratio and / or the number of cells of the charge MOS transistor, where M is greater than 1.

[0041] According to at least one embodiment of the present disclosure, the discharge MOS transistor and the discharge calibration MOS transistor are NMOS transistors or PMOS transistors, and the M value is 100, 1000 or 10000.

[0042] According to another aspect of the present disclosure, a battery management chip is integrated with the temperature coefficient calibration device as described in any one of the above items. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0044] Figure 1 A schematic diagram of a temperature coefficient calibration device according to an embodiment of the present disclosure is shown.

[0045] Figure 2 A schematic diagram of a calibration device according to an embodiment of the present disclosure is shown.

[0046] Figure 3 A calibration device according to one embodiment of the present disclosure is shown.

[0047] Figure 4 A calibration circuit according to another embodiment of the present disclosure is shown.

[0048] Figure 5 A calibration circuit according to another embodiment of the present disclosure is shown.

[0049] Figure 6 A schematic diagram of a battery management chip according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0050] The present disclosure is further described in detail below in conjunction with the accompanying drawings and implementations. It is understood that the specific implementations described herein are only used to explain the relevant content, rather than to limit the present disclosure. It should also be noted that, for ease of description, only the parts related to the present disclosure are shown in the accompanying drawings.

[0051] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure can be combined with each other. The technical solution of the present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] Unless otherwise specified, the exemplary embodiments / embodiments shown will be understood as providing exemplary features of various details of some ways in which the technical concept of the present disclosure can be implemented in practice. Therefore, unless otherwise specified, the features of the various embodiments / embodiments can be combined, separated, interchanged and / or rearranged in addition without departing from the technical concept of the present disclosure.

[0053] The use of cross-hatching and / or shading in the accompanying drawings is generally used to make the boundaries between adjacent components clear. As such, unless otherwise specified, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for the specific materials, material properties, dimensions, proportions, commonalities between the components shown, and / or any other characteristics, attributes, properties, etc. of the components. In addition, in the accompanying drawings, the sizes and relative sizes of the components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific process sequence can be performed in a different order than described. For example, two successively described processes can be performed substantially simultaneously or in an order opposite to the described order. In addition, the same figure numbers represent the same components.

[0054] When a component is referred to as being "on" or "over," "connected to," or "coupled to" another component, the component may be directly on, directly connected to, or directly coupled to the other component, or intervening components may be present. However, when a component is referred to as being "directly on," "directly connected to," or "directly coupled to" another component, there are no intervening components. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, etc., with or without intervening components.

[0055] For descriptive purposes, the present disclosure may use spatially relative terms such as "under," "beneath," "under," "down," "over," "upper," "above," "higher," and "side (e.g., as in "sidewall")," to describe the relationship of one component to another (other) component as shown in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, components described as "under" or "beneath" other components or features would subsequently be positioned "over" the other components or features. Thus, the exemplary term "under" can encompass both the "above" and "below" orientations. Furthermore, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0056] The terms used here are for the purpose of describing specific embodiments, and are not intended to be restrictive. As used here, unless the context clearly indicates otherwise, the singular forms "one (kind, person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise" and / or "include" and their variations are used in this specification, it is explained that there are stated features, integral bodies, steps, operations, parts, assemblies and / or their groups, but it is not excluded that there are or add one or more other features, integral bodies, steps, operations, parts, assemblies and / or their groups. It should also be noted that, as used here, the terms "substantially", "approximately" and other similar terms are used as approximate terms and not as degree terms, so that they are used to explain the inherent deviations of the measured values, calculated values ​​and / or the values ​​provided that will be recognized by those of ordinary skill in the art.

[0057] According to one embodiment of the present disclosure, a temperature coefficient calibration device is provided, wherein the temperature coefficient calibration device can be used to calibrate the temperature coefficients of a charging MOS transistor and a discharging MOS transistor, thereby calibrating the on-resistance of the two transistors, etc.

[0058] In the present disclosure, various MOS transistors may be integrated into one device, which can ensure that various transistors have the same temperature coefficient or a variation in the temperature coefficient.

[0059] Figure 1 A temperature coefficient calibration device according to one embodiment of the present disclosure is shown.

[0060] like Figure 1As shown, the temperature coefficient calibration device may include: a discharge MOS transistor 110 and a charge MOS transistor 120. In the present disclosure, an NMOS transistor is used as an example for description, but those skilled in the art should understand that it may also be a PMOS transistor. In addition, in the case of an NMOS transistor, a series circuit formed by the discharge MOS transistor 110 and the charge MOS transistor 120 may be connected between the negative terminal of the battery pack and the negative terminal of the load / charger, and in the case of a PMOS transistor, a series circuit formed by the discharge MOS transistor 110 and the charge MOS transistor 120 may be connected between the positive terminal of the battery pack and the positive terminal of the load / charger.

[0061] The gate of the discharge MOS transistor 110 is connected to the discharge control signal DSG to control the discharge of the battery pack, wherein the source of the discharge MOS transistor 110 is connected to one end B- of the battery pack. When only the discharge MOS transistor 110 is included, the drain of the discharge MOS transistor 110 can be connected to the load / charger terminal. The discharge MOS transistor 110 can include a parasitic diode.

[0062] In addition, a voltage stabilizing diode 210 may be connected between the gate and source of the discharge MOS transistor 110 to prevent the gate of the discharge MOS transistor 110 from being broken down. Figure 1 In the figure, a Zener diode is shown, but other types of diodes can also be selected, which can include two Zener diodes connected in reverse series.

[0063] Furthermore, the gate of the discharge MOS transistor 110 may be connected to the discharge control signal DSG via a resistor to provide electrostatic protection, wherein the resistance value of the resistor may be 1K ohm.

[0064] The discharge calibration MOS transistor 111 can calibrate the temperature coefficient of the discharge MOS transistor.

[0065] The drain of the discharge calibration MOS transistor 111 is connected to the drain of the discharge MOS transistor 110, the gate of the discharge calibration MOS transistor 111 is connected to the discharge control signal DSG, and the source of the discharge calibration MOS transistor 111 serves as the discharge calibration terminal SD1. The discharge calibration MOS transistor 111 may include a parasitic diode. Although it is shown here that the discharge calibration MOS transistor and the discharge MOS transistor use the same discharge control signal DSG, the two may also use different discharge control signals.

[0066] In addition, a Zener diode (for example, in the form of a Zener diode 210 ) may be connected between the gate and source of the discharge calibration MOS transistor 111 to prevent the gate of the discharge calibration MOS transistor 111 from being broken down.

[0067] The gate of the discharge calibration MOS transistor 111 may be connected to the discharge control signal DSG via a resistor to provide electrostatic protection, wherein the resistance of the resistor may be 100K ohms.

[0068] The channel length-to-width ratio of the discharge calibration MOS transistor 111 and the channel length-to-width ratio of the discharge MOS transistor 110 are 1:M, where M is greater than 1. For example, the value of M may be 100, 1000, 10000, and so on.

[0069] In addition, other discharge calibration MOS transistors 112 may be included, wherein the number of other discharge calibration MOS transistors may be N, wherein N is an integer greater than or equal to 1. The channel length-to-width ratio of the Nth discharge calibration MOS transistor and the channel length-to-width ratio of the discharge MOS transistor 110 are 1:M to the N-1th power, wherein i is an integer greater than or equal to 1, wherein the value of i changes with the value of N. For example, the M value is an integer multiple of 10, preferably 100. The channel length-to-width ratio of the Nth discharge calibration MOS transistor to the charging MOS transistor is 1:M to the N-1th power. For example, the channel length-to-width ratio of transistor 111 to transistor 110 is 1:100, the channel length-to-width ratio of transistor 112 to transistor 110 is 1:1000, and the channel length-to-width ratio of other transistors to transistor 110 is 1:10000, etc. For example, depending on the type of MOS transistor, when the MOS transistor is characterized by the number of cells, the above-mentioned relationship of the channel aspect ratio can be expressed as the relationship of the number of cells (the number of cells connected in parallel).

[0070] The configuration of other discharge calibration MOS transistors may be the same as the configuration of the discharge calibration MOS transistor 111 , and for the sake of brevity, it will not be described in detail here.

[0071] For example Figure 1 As shown, the gates of the discharge calibration MOS transistors 111 and 112 can be controlled by the discharge control signal DSG to be turned on and off, and the sources can be used as the discharge calibration terminals SD1 and SD2.

[0072] According to a further embodiment of the present disclosure, the temperature coefficient calibration device further includes: a charging MOS transistor 120, the gate of which is connected to the charging control signal CG to control the charging of the battery pack, wherein the drain of the charging MOS transistor 120 is connected to the drain of the discharging MOS transistor 110, and the source of the charging MOS transistor 120 is connected to one end P- of the load / charger. The charging MOS transistor may include a parasitic diode.

[0073] In addition, a voltage stabilizing diode 220 may be connected between the gate and source of the charging MOS transistor 120 to prevent the gate of the charging MOS transistor 120 from being broken down. Figure 1 In the figure, a Zener diode is shown, but other types of diodes can also be selected, which can include two Zener diodes connected in reverse series.

[0074] Furthermore, the gate of the charging MOS transistor 120 may be connected to the discharge control signal DSG via a resistor to provide electrostatic protection, wherein the resistance value of the resistor may be 1K ohm.

[0075] Similar to the discharge calibration MOS transistor of the discharge MOS transistor 110 , the charge MOS transistor 120 may also include a plurality of charge calibration MOS transistors 121 and 122 .

[0076] In addition, a voltage regulator diode may be connected between the gate and source of the charge calibration MOS transistor to prevent the gate of the charge calibration MOS transistor from being broken down. Moreover, the gate of the charge calibration MOS transistor may be connected to the charge control signal CHG via a resistor to provide electrostatic protection, wherein the resistance value of the resistor may be 100K ohms.

[0077] The channel length-to-width ratio of the charging calibration MOS transistor and the channel length-to-width ratio of the charging MOS transistor 120 are 1:M, where M is greater than 1. For example, the value of M can be 100, 1000, 10000, etc. The number of charging calibration MOS transistors is N, where N is an integer greater than or equal to 1, and the channel length-to-width ratio of the Nth charging calibration MOS transistor and the channel length-to-width ratio of the charging MOS transistor are 1:M to the N-1th power, where i is an integer greater than or equal to 1, and the value of i changes with the value of N. The value of M can be an integer multiple of 10, preferably 100. The channel length-to-width ratio of the Nth charging calibration MOS transistor and the charging MOS transistor is 1:M to the N-1th power.

[0078] For example, the channel length-to-width ratio of transistor 121 to transistor 120 is 1:100, the channel length-to-width ratio of transistor 122 to transistor 120 is 1:1000, and the channel length-to-width ratio of other transistors to transistor 120 is 1:10000, etc. For example, depending on the type of MOS transistor, when the MOS transistor is characterized by the number of cells, the relationship of the channel length-to-width ratios mentioned above can be expressed as the relationship of the number of cells (the number of cells connected in parallel).

[0079] For example Figure 1 As shown, the gates of the charging calibration MOS transistors 121 and 122 can be controlled by the charging control signal CHG to be turned on and off, and the sources can be used as the charging calibration terminals SC1 and SC2.

[0080] In the present disclosure, the discharge MOS transistor and the discharge calibration MOS transistor are transistors of the same type, the charge MOS transistor and the charge calibration MOS transistor are transistors of the same type, or all four are MOS transistors of the same type.

[0081] It should be understood by those skilled in the art that the larger the channel width-to-length ratio of the MOS transistor, the smaller the on-resistance, and thus the larger the current flowing through it. In the present disclosure, by using a charging and discharging MOS transistor with a large width-to-length ratio, its on-resistance will be very small, so that the energy consumed in the charging and discharging circuit is very small. When it is necessary to detect the current, a detection MOS transistor with a relatively small channel width-to-length ratio is used, so that its on-resistance is large, and therefore the current flowing through it is small, which can facilitate detection without the need for subsequent acquisition units and other requirements for withstanding large currents. At the same time, since the detection MOS transistor is in the detection branch, this will not affect the normal charging and discharging circuit, such as consuming the power of the battery.

[0082] Although the charging current and discharging current can be detected by the on-resistance of the charging and discharging MOS transistors, it should be noted that in the actual manufacturing process, the on-resistance cannot be manufactured to an ideal state, and as the temperature changes, the on-resistance of the transistor will also change due to the temperature coefficient. For example, as the temperature changes, it may change by ±20%. Therefore, it will affect the detection effect.

[0083] Therefore, in order to solve the problems in the prior art, a calibration device is proposed in the present disclosure.

[0084] Figure 2 and Figure 3 A calibration device according to an embodiment of the present disclosure is shown. The following description will be made by taking the discharge calibration MOS transistor 111 as an example. The same principle can be applied to other discharge calibration MOS transistors, and the same principle can also be applied to charge calibration MOS transistors.

[0085] The calibration device may include a first current source 310 and a second current source 320 , an external resistor 410 , a first analog-to-digital converter 510 and a second analog-to-digital converter 520 .

[0086] The first current source 310 is used to provide a first calibration current Ical1, and the second current source 320 is used to provide a second calibration current Ical2, and the current values ​​of the first calibration current and the second calibration current can be equal. In addition, preferably, the first calibration current source 310 and the second current source 320 can generate the first calibration current Ical1 and the second calibration current Ical2 according to the voltage VB+ (the voltage at the B+ terminal) of the battery pack. More preferably, the first current source and the second current source can be the same current source.

[0087] The second current source 320 is connected to the negative terminal B− of the battery pack via the external resistor 410 , and the first current source 310 is connected to the discharge calibration MOS transistor, for example, can be connected to the source of the discharge calibration MOS transistor 111 .

[0088] The second analog-to-digital converter 520 may be used to measure the voltage across the series circuit of the discharge MOS transistor 110 and the charge MOS transistor 120 .

[0089] In the present disclosure, the voltage VDS1 between the D terminal and the S1 terminal of the discharge MOS transistor 110 is (VB1-VP1) / 2, where VB1 is the voltage at the negative terminal B- of the battery pack, and VP1 is the voltage at the negative terminal P- of the load / charger. Here, the voltage VDS1 can be obtained by half of the voltage measured by the second analog-to-digital converter.

[0090] When the first current source 310 provides the first calibration current Ical1, the voltage at the source terminal SD1 of the discharge calibration MOS transistor will be equal to VSD1=Ron1M*Ical1+IL*Ron1+Ical1*Ron1, where Ron1M is the on-resistance of the transistor 111, IL is the charging current, and Ron1 is the on-resistance of the transistor 110.

[0091] Because Ron1 is 1 / 100, 1 / 1000, or 1 / 10000 of Ron1M, the voltage VSD1 will be roughly equal to Ron1M*Ical1+IL*Ron1=V2 (Ical1 is set to be small, which is a small current). IL*Ron1=V1 / 2=(VB1-VP1) / 2, where the voltage V1 collected by the second analog-to-digital conversion unit is (VB1-VP1), so Ron1M*Ical1=V2-V1 / 2, where V2 is Figure 1 The difference V2 between the voltage at the connection point a between the first current source 310 and the source of the discharge calibration MOS transistor 111 and the voltage at the negative terminal B− of the battery pack is collected by the first analog-to-digital converter 510 .

[0092] Thus Ron1M=(V2-V1 / 2) / Ical1.

[0093] The first analog-to-digital converter 510 can also measure the voltage between b and B- at both ends of the external resistor 410, where the voltage can be expressed as V3, where V3=Ical2*Rext, Ical2 is the second calibration current provided by the second current source 320, and Rext is the resistance value of the external resistor. The second calibration current can be the same as the first calibration current. Although two different current sources are shown in the figure, it can also be implemented by using one current source, through which two branches are respectively divided to connect the external resistor and the discharge calibration MOS transistor. The voltage V3 can be measured by the first analog-to-digital converter 510.

[0094] so,

[0095] Because the external resistor can be a zero temperature coefficient resistor or a low temperature coefficient resistor, for example, the temperature coefficient is usually 10ppm / ℃. The change of Ron1M with temperature will be Because Ron1M and Ron1 have a predetermined ratio, and the ratio is set as a constant, the temperature variation of Ron1 can be obtained according to the temperature variation of Ron1M. Therefore, after knowing the temperature variation of Ron1, calibration and compensation can be performed based on it.

[0096] In the technical solution of the present disclosure, the sampling resistor is omitted. The sampling resistor is usually connected in series with the charge and discharge MOS transistor, and the charging voltage or the discharging voltage is obtained by collecting the voltage across the sampling resistor. In the present disclosure, it is completely omitted, which can reduce the power consumption caused by it and save costs.

[0097] In addition, in the present disclosure, although it is described that the voltages at the S1 and S2 terminals are measured by the second analog-to-digital converter, it should be noted that the second analog-to-digital converter can also measure the voltage between the S1 and D terminals, where D is the drain terminal of the discharge MOS transistor 110.

[0098] In the actual manufacturing process, although the D terminal can be led out and its voltage can be measured, in order to lead out the D terminal separately by means of wires, etc., the manufacturing cost will be greatly increased due to the limitation of the device manufacturing process.

[0099] Therefore, in the present disclosure, because the charging calibration MOS transistor 121 needs to detect the temperature coefficient of the charging MOS tube, and in the manufacturing process, according to the structure of the present disclosure, the drains of the transistors 110, 111, 120 and 121 need to be connected. Therefore, in order to avoid the process complexity and cost increase caused by the separate lead-out of the D terminal, in the present disclosure, when the temperature coefficient of the discharge MOS transistor 110 is calibrated, the transistor 121 can be used to implement it. The specific implementation method will be described below. Moreover, in the process of integrating various MOS tubes into one chip, if it is necessary to measure the drain voltage separately, a separate pin is required at this time, because the increase of the pin may cause the increase of the chip size, etc.

[0100] Therefore, in order to further solve this technical problem, a further improvement scheme is provided in the present disclosure, such as Figure 4 As shown, when measuring the temperature coefficient change of the discharge MOS transistor 110, the discharge MOS transistor 110 and the discharge calibration MOS transistor 111 can be turned on, and the charge calibration MOS transistor 121 can also be turned on. Here, because the temperature coefficient of the charge MOS transistor 120 needs to be calibrated, the charge calibration MOS transistor 121 needs to be set accordingly. At this time, the drain voltage can be measured by using the charge calibration MOS transistor 121.

[0101] In the present disclosure, because the voltage at the P-terminal is not stable and sometimes has a large deviation, the method of obtaining the voltage V1 by measuring the voltage between the B-terminal and the P-terminal in the above embodiment may not be accurate. Therefore, the preferred technical solution in the present disclosure is to measure the voltage between the drain D and the source terminal S1 to calibrate the temperature coefficient of the discharge MOS transistor 110, and the temperature coefficient of the charging MOS transistor 120 can be calibrated by measuring the voltage between the drain D and the source terminal S2.

[0102] The temperature coefficient compensation of the discharge MOS transistor 110 is taken as an example for explanation. The second analog-to-digital converter 520 can connect the source terminal (B-terminal) of the discharge MOS transistor 110 and the source terminal S2M of the charge calibration MOS transistor 121. In this way, when the charge calibration MOS transistor 121 is turned on, the voltage between the source and the drain of the discharge MOS transistor 110 can be obtained by the second analog-to-digital converter connected between the S2M terminal and the S1 terminal. And further according to the formula mentioned above To obtain the change of the temperature coefficient, V1 / 2 in this formula is the voltage between the source and the drain of the discharge MOS transistor 110.

[0103] In addition, the measurement of the temperature variation of the discharge MOS transistor 110 is described above, and the measurement of the charge MOS transistor 120 can be carried out in the same manner, that is, the first calibration current can be provided to the SC1 terminal through the current source, and through the above process, the temperature variation of the charge MOS transistor 120 can also be achieved. It should be understood by those skilled in the art that in the process of calibrating the temperature coefficient of the charge MOS transistor 120, the first current source 310 can be connected to the SC1 terminal, and the series circuit of the second current source and the resistor 410 can be connected to the B-terminal or the P-terminal.

[0104] At this time, transistors 120 and 121 need to be turned on, and transistor 111 also needs to be turned on, and the second analog-to-digital converter 520 can measure the voltage between the S2 terminal and the D terminal as the related term of V1 / 2 in the above formula. In addition, the second analog-to-digital converter can also measure the voltage between the S1 terminal and the S2 terminal, or can also measure the voltage between the S1 terminal and the SC1 terminal, and so on.

[0105] If the temperature coefficients of the discharge MOS transistor 110 and the charge MOS transistor 120 are not calibrated, the on-resistances of the two will have temperature coefficients. For example, in the case of -40°C to 80°C, the change of the two will exceed 20%. Therefore, if the temperature change or temperature coefficient of the two is not calibrated, the detection of the charging current or the discharging current will also have at least a 20% error. Therefore, in the present disclosure, it is innovatively proposed that when calibrating the charge and discharge MOS tube (large tube), a calibration current can be injected into the corresponding charge and discharge calibration MOS transistor (small tube) through a current source, and the voltage across the small tube is measured (the voltage of the small tube is obtained in a simple way). According to the proportional relationship between the large and small tubes, the temperature coefficient of the large tube is obtained accordingly, thereby providing a basis for the subsequent charge and discharge current compensation.

[0106] Further, in the above manner, during the calibration process, the acquisition of V2 will be affected by the charge and discharge current, such as the relevant formula of V2 described above. In this way, it may affect the actual charge and discharge process during the calibration process, or the charge and discharge process may affect the calibration process. According to a further embodiment of the present disclosure, an improved embodiment is further provided.

[0107] See also Figure 5 , may include two discharge calibration MOS transistors 111 , 112 and two charge calibration MOS transistors 121 , 122 .

[0108] Continuing to take the temperature coefficient calibration of the discharge MOS transistor 110 as an example, the drains of the discharge calibration MOS transistors 111 and 112 are connected to the drain of the discharge MOS transistor 110 , and the drains of the charge calibration MOS transistors 121 and 122 are connected to the drain of the charge MOS transistor 120 .

[0109] A source terminal SD2 of the discharge calibration MOS transistor 112 is connected to the first current source, and a source terminal SD1 of the discharge calibration MOS transistor 111 is connected to the B-terminal of the battery pack.

[0110] During the calibration process, the discharge calibration MOS transistor 111 and the discharge calibration MOS transistor 112 can be turned on. At the same time, the second analog-to-digital converter can measure the voltage across the transistor 110 and the transistor 120. As described above, more preferably, one of the charge calibration MOS transistor 121 and the charge calibration MOS transistor 122 is turned on, and the second analog-to-digital converter can measure the B-end of the battery pack and the source voltage of the turned-on transistor of the charge calibration MOS transistor 121 and the charge calibration MOS transistor 122. In this way, the charge and discharge currents can be made to have no interference with the calibration.

[0111] In addition, the second analog-to-digital converter can measure the voltage between the S1 terminal and the S2 terminal, can measure the voltage between the S1 terminal and the D terminal, can measure the voltage between the S1 terminal and the SC1 terminal, can measure the voltage between the S1 terminal and the SC2 terminal, and so on.

[0112] The following will refer to Figure 5 The discharge calibration MOS transistor 111 and the discharge calibration MOS transistor 112 are turned on, and the charge calibration MOS transistor 121 is turned on. Wherein V3 is the voltage between the two ends b and B- of the external resistor 410 , V2 is the voltage between the end a and the end B-, and V4 is the voltage between the end D and the end B- of the transistor 111 .

[0113] In addition, when transistors 111 and 112 are set to be the same, V2 will be equal to 2*V4, so the above formula can be transformed into

[0114] According to this method, greater advantages can be obtained. Although those skilled in the art understand that a constant current source can provide a constant current, in actual manufacturing, it is almost impossible to provide a completely constant current, and the higher the accuracy of the current provided, the higher the cost.

[0115] However, according to this embodiment of the present disclosure, the accuracy of the current provided by the constant current source can be ignored. For example, it can be seen from the above formula that: It can be independent of the constant current source, which can effectively reduce costs.

[0116] The present disclosure also provides a battery management chip, such as Figure 6 As shown, the battery management chip may include the above-mentioned calibration device. It should be noted that, in the battery management chip, the various MOS transistors described above may be integrated into the one battery management chip.

[0117] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0118] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0119] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A high-precision, low-power consumption temperature coefficient calibration device, used for calibrating the temperature coefficient of a MOS transistor, wherein the MOS transistor is a charging MOS transistor and a discharging MOS transistor for controlling the charging and discharging of a battery / battery pack, the drain of the charging MOS transistor and the drain of the discharging MOS transistor are connected to form a series circuit, the gate of the charging MOS transistor is connected to a charging control signal to control the charging of the battery / battery pack, the gate of the discharging MOS transistor is connected to a discharging control signal to control the discharging of the battery / battery pack, the source of the discharging MOS transistor is connected to the negative end of the battery / battery pack, the source of the charging MOS transistor is connected to the negative end of a load / charger, the positive end of the battery / battery pack is connected to the positive end of the load / charger, and a voltage stabilizing diode is connected between the gate and the source of the discharging MOS transistor, characterized in that: include: a discharge calibration MOS transistor and / or a charge calibration MOS transistor, wherein the drain of the discharge calibration MOS transistor is connected to the drain of the discharge MOS transistor, and the gate of the discharge calibration MOS transistor is connected to a discharge control signal, and / or the drain of the charge calibration MOS transistor is connected to the drain of the charge MOS transistor, and the gate of the charge calibration MOS transistor is connected to a charge control signal; a first current source connected to a source of the discharge calibration MOS transistor and / or connected to a source of the charge calibration MOS transistor; as well as A calibration unit, wherein the calibration unit obtains a temperature coefficient change of the discharge calibration MOS transistor based on a voltage between a source and a drain of the discharge calibration MOS transistor and obtains the temperature coefficient change of the discharge MOS transistor according to a relationship between the discharge calibration MOS transistor and the discharge MOS transistor, and / or obtains a temperature coefficient change of the charge calibration MOS transistor based on a voltage between a source and a drain of the charge calibration MOS transistor and obtains the temperature coefficient change of the charge MOS transistor according to a relationship between the charge calibration MOS transistor and the charge MOS transistor.

2. The temperature coefficient calibration device according to claim 1, characterized in that: The charging MOS transistor, the discharging MOS transistor, the discharging calibration MOS transistor and the charging calibration MOS transistor are MOS transistors of the same type, and the channel length-to-width ratio and / or the number of cells of the discharging MOS transistor are proportional to the channel length-to-width ratio and / or the number of cells of the discharging calibration MOS transistor, and the channel length-to-width ratio and / or the number of cells of the charging MOS transistor are proportional to the channel length-to-width ratio and / or the number of cells of the charging calibration MOS transistor.

3. The temperature coefficient calibration device according to claim 2, characterized in that: The device further comprises a first resistor, which is a zero temperature coefficient resistor or a low temperature coefficient resistor, one end of which is connected to the second current source, and the other end of which is connected to the negative terminal of the battery pack.

4. The temperature coefficient calibration device according to claim 3, characterized in that: The first current source and the second current source are the same current source or different current sources. In the case of different current sources, the current value of the first calibration current provided by the first current source and the current value of the second calibration current provided by the second current source are equal or unequal.

5. The temperature coefficient calibration device according to claim 3, characterized in that: Also includes: a first analog-to-digital converter, the first analog-to-digital converter acquiring a voltage across the first resistor, and a voltage between a source of the discharge calibration MOS transistor and / or a source of the charge calibration MOS transistor and a negative terminal of a battery / battery pack or a negative terminal of a load / charger; as well as a second analog-to-digital converter, the second analog-to-digital converter directly or indirectly acquiring a voltage between a source and a drain of a charge calibration MOS transistor and / or a voltage between a source and a drain of a discharge calibration MOS transistor, The first analog-to-digital converter and the second analog-to-digital converter are different analog-to-digital converters or the same analog-to-digital converters.

6. The temperature coefficient calibration device according to claim 5, characterized in that: The number of the discharge calibration MOS transistor is one.

7. The temperature coefficient calibration device according to claim 6, characterized in that: When the temperature coefficient of the discharge MOS transistor is calibrated, the discharge calibration MOS transistor and the discharge MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source of the discharge MOS transistor and the source of the charging MOS transistor, and obtains the temperature coefficient change of the discharge calibration MOS transistor based on the voltage between the source and the drain of the discharge calibration MOS transistor, the voltage between the source and the drain of the discharge MOS transistor, and the voltage across the first resistor.

8. The temperature coefficient calibration device according to claim 7, characterized in that: In the case of including a discharge calibration MOS transistor and a charge calibration MOS transistor, the drains of the discharge calibration MOS transistor and the charge calibration MOS transistor are both connected to the drain of the discharge MOS transistor, and in the case of calibrating the temperature coefficient of the discharge MOS transistor, the discharge calibration MOS transistor, the discharge MOS transistor and the charge calibration MOS transistor are turned on, and the second analog-to-digital converter measures a first voltage between the source of the discharge MOS transistor and the source of the charge calibration MOS transistor, and obtains the temperature coefficient change of the discharge calibration MOS transistor based on the first voltage and the voltage across the first resistor.

9. The temperature coefficient calibration device according to claim 7, characterized in that: When the temperature coefficient of the discharge MOS transistor is calibrated, the discharge calibration MOS transistor and the discharge MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the discharge MOS transistor or measures the voltage between the source and the drain of the discharge calibration MOS transistor, and combines the voltage between the source and the drain of the discharge MOS transistor and the voltage across the first resistor to obtain the change in the temperature coefficient of the discharge calibration MOS transistor.

10. The temperature coefficient calibration device according to claim 5, characterized in that: The number of the charging calibration MOS transistor is one.

11. The temperature coefficient calibration device according to claim 10, characterized in that: When the temperature coefficient of the charging MOS transistor is calibrated, the charging calibration MOS transistor and the charging MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source of the discharging MOS transistor and the source of the charging MOS transistor, and obtains the temperature coefficient change of the charging calibration MOS transistor based on the voltage between the source and the drain of the charging calibration MOS transistor, the voltage between the source and the drain of the charging MOS transistor, and the voltage across the first resistor.

12. The temperature coefficient calibration device according to claim 10, characterized in that: In the case of including a discharge calibration MOS transistor and a charge calibration MOS transistor, the drains of the charge calibration MOS transistor and the discharge calibration MOS transistor are both connected to the drain of the charge MOS transistor, and in the case of calibrating the temperature coefficient of the charge MOS transistor, the charge calibration MOS transistor, the charge MOS transistor and the discharge calibration MOS transistor are turned on, and the second analog-to-digital converter measures a second voltage between the source of the charge MOS transistor and the source of the discharge calibration MOS transistor, and obtains the temperature coefficient change of the charge calibration MOS transistor based on the second voltage and the voltage across the first resistor.

13. The temperature coefficient calibration device according to claim 10, characterized in that: When the temperature coefficient of the charging MOS transistor is calibrated, the charging calibration MOS transistor and the charging MOS transistor are turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the discharging MOS transistor or the voltage between the source and the drain of the charging calibration MOS transistor, and combines the voltage between the source and the drain of the charging MOS transistor and the voltage across the first resistor to obtain the change in the temperature coefficient of the charging calibration MOS transistor.

14. The temperature coefficient calibration device according to claim 5, characterized in that: The number of the discharge calibration MOS transistors is two, and the drains of the first discharge calibration MOS transistor and the second discharge calibration MOS transistor of the two discharge calibration MOS transistors are both connected to the drain of the discharge MOS transistor, and the source of the first discharge calibration MOS transistor is connected to the first current source, the source of the second discharge calibration MOS transistor is connected to the negative terminal of the battery / battery pack, and the gates of the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are both connected to the discharge control signal.

15. The temperature coefficient calibration device according to claim 14, characterized in that: When the temperature coefficient of the discharge MOS transistor is calibrated, the discharge MOS transistor, the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are all turned on, the second analog-to-digital converter measures a third voltage between the source and the drain of the second discharge calibration MOS transistor, and the first analog-to-digital converter measures a fourth voltage between the source of the first discharge calibration MOS transistor and the source of the second discharge calibration MOS transistor, and the change in the temperature coefficient of the discharge calibration MOS transistor is obtained according to the third voltage, the fourth voltage and the voltage across the first resistor.

16. The temperature coefficient calibration device according to claim 14, characterized in that: When the temperature coefficient of the discharge MOS transistor is calibrated, the discharge MOS transistor, the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are all turned on, the first discharge calibration MOS transistor and the second discharge calibration MOS transistor are the same MOS transistor, and a fourth voltage between the source of the first discharge calibration MOS transistor and the source of the second discharge calibration MOS transistor is measured by the first analog-to-digital converter, and the change in the temperature coefficient of the discharge calibration MOS transistor is obtained according to the fourth voltage and the voltage across the first resistor.

17. The temperature coefficient calibration device according to claim 14, characterized in that: In the case of calibrating the temperature coefficient of the discharge MOS transistor, the discharge MOS transistor, the first discharge calibration MOS transistor, and the second discharge calibration MOS transistor are all turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the first discharge calibration MOS transistor, the voltage between the source of the first discharge calibration MOS transistor and the source of the second discharge calibration MOS transistor, the voltage between the source and the drain of the discharge MOS transistor, or the voltage between the source of the discharge MOS transistor and the source of the charge MOS transistor; The first analog-to-digital converter measures a fourth voltage between a source of the first discharge calibration MOS transistor and a source of the second discharge calibration MOS transistor, The temperature coefficient change of the discharge calibration MOS transistor is obtained according to the voltage measured by the second analog-to-digital converter, the fourth voltage and the voltage across the first resistor.

18. The temperature coefficient calibration device according to claim 15, characterized in that: In the case of including a charge calibration MOS transistor, the charge calibration MOS transistor is turned on, and the second analog-to-digital converter measures the voltage between the source of the second discharge calibration MOS transistor and the source of the charge calibration MOS transistor to obtain the third voltage.

19. The temperature coefficient calibration device according to claim 5, characterized in that: The number of the charging calibration MOS transistors is two, and the drains of the first charging calibration MOS transistor and the second charging calibration MOS transistor of the two charging calibration MOS transistors are both connected to the drain of the charging MOS transistor, and the source of the first charging calibration MOS transistor is connected to the first current source, the source of the second charging calibration MOS transistor is connected to the negative end of the battery / battery pack or the negative end of the load / charger, and the gates of the first charging calibration MOS transistor and the second charging calibration MOS transistor are both connected to the charging control signal.

20. The temperature coefficient calibration device according to claim 19, characterized in that: When the temperature coefficient of the charging MOS transistor is calibrated, the charging MOS transistor, the first charging calibration MOS transistor and the second charging calibration MOS transistor are all turned on, the second analog-to-digital converter measures a fifth voltage between the source and the drain of the second charging calibration MOS transistor, and the first analog-to-digital converter measures a sixth voltage between the source of the first charging calibration MOS transistor and the source of the second charging calibration MOS transistor, and the change in the temperature coefficient of the charging calibration MOS transistor is obtained based on the fifth voltage, the sixth voltage and the voltage across the first resistor.

21. The temperature coefficient calibration device according to claim 19, characterized in that: When the temperature coefficient of the charging MOS transistor is calibrated, the charging MOS transistor, the first charging calibration MOS transistor and the second charging calibration MOS transistor are all turned on, the first charging calibration MOS transistor and the second charging calibration MOS transistor are the same MOS transistor, and a sixth voltage between the source of the first charging calibration MOS transistor and the source of the second charging calibration MOS transistor is measured by the first analog-to-digital converter, and the temperature coefficient change of the charging calibration MOS transistor is obtained according to the sixth voltage and the voltage across the first resistor.

22. The temperature coefficient calibration device according to claim 19, characterized in that: In the case of calibrating the temperature coefficient of the charging MOS transistor, the charging MOS transistor, the first charging calibration MOS transistor, and the second charging calibration MOS transistor are all turned on, and the second analog-to-digital converter measures the voltage between the source and the drain of the first charging calibration MOS transistor, the voltage between the source of the first charging calibration MOS transistor and the source of the second charging calibration MOS transistor, the voltage between the source and the drain of the charging MOS transistor, or the voltage between the source of the charging MOS transistor and the source of the discharging MOS transistor; The first analog-to-digital converter measures a sixth voltage between a source of the first charging calibration MOS transistor and a source of a second charging calibration MOS transistor, The temperature coefficient change of the charge calibration MOS transistor is obtained according to the voltage measured by the second analog-to-digital converter, the sixth voltage and the voltage across the first resistor.

23. The temperature coefficient calibration device according to claim 20, characterized in that: In the case of including a discharge calibration MOS transistor, the discharge calibration MOS transistor is turned on, and the second analog-to-digital converter measures a voltage between a source of the second charge calibration MOS transistor and a source of the discharge calibration MOS transistor to obtain the fifth voltage.

24. The temperature coefficient calibration device according to any one of claims 2 to 23, characterized in that: The channel length-to-width ratio and / or the number of cells of the discharge calibration MOS transistor is 1:M with the channel length-to-width ratio and / or the number of cells of the discharge MOS transistor, and / or the channel length-to-width ratio and / or the number of cells of the charge calibration MOS transistor is 1:M with the channel length-to-width ratio and / or the number of cells of the charge MOS transistor, wherein M is greater than 1.

25. The temperature coefficient calibration device according to claim 24, characterized in that: The discharge MOS transistor and the discharge calibration MOS transistor are NMOS transistors or PMOS transistors, and the M value is 100, 1000 or 10000.

26. A battery management chip, characterized in that: The device is integrated with a high-precision, low-power consumption temperature coefficient calibration device as claimed in any one of claims 1 to 25.

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